program Pi;

{$APPTYPE CONSOLE}

uses
  SysUtils;

var
 n0, n, i: integer;
 x, y, p: real;

begin
 randomize;
  n0:=0;
 n:=0;
 for i:= 0 to 1000000 do
 begin
  x:=2*random;
 y:=2*random;

  if ((x-1)*(x-1))+((y-1)*(y-1))<=1 then
  n0:=n0+1;
  n:=n+1;
  end;
  p:=4*n0/n;
  write (p:0:12);
  readln;
end.
 